Fusible link.



G. I. ROGKWOOD.

, PUSIBLE LINK.

APPLIOATION FILED SEPT. 22, 190e.

Patented Feb. 2, 1909.

UNITED srnfrns PATENT cerros.

FUSIBLE LINK.

No. 911,162. l

Specification of Letters Patent Patented Feb. 2, 1909.

Application filed September 22, 1908. Serial No. 454,159.

To all ywhom it may concern:-

Be it known that I, GEORGE I. RocKwooD, a citizen of the United States, residing at Vorcester, in the county of Worcester and Commonwealth of Massacl'iusetts, have invented a new and useful Improvement in a Fusible Link, of which the following is a specifica-tion, accompanied by drawings forming a part of the same, in whichi Figure 1 denotes top view of my iinproved fusible link. Fig. 2 1s a side View shown 1n central section, and Fig. ,3 is a transverse sectional view on the plane of the broken line 3-3, Figs. l and 2.

Similar reference letters and figures refer to similar parts in the different views.

The object of mv present invention is to l provide a fusible lirik adapted to forma constituent part of a tensile. sup ort such, for example, as that Aemployed in ioldin up fire proof doors or shutters between the r ifferent departments of stores or warehouses, said fusible` link'being designed lto yield at a predetermined degree of heat and allow the door or shutter to fall.

Appliances for fireprotection of the' kind referred to have been heretofore employed provided with a tensile support having a yielding link, comprising two members soldered together by a material fusible at a determinate degree of heat. In links of this character, however, the adhesive force is exerted at right angles to the line of tensile strain, so that the power required to separate the members is determined by the adhesion of one to the other and this, in certain cases, may yield before the soldering material has become entirely fused by heat.

In my improved fusible link I provide the two contacting members with abutting sur' faces placed at an oblique angle lto the line of tensile strain, and I hold these surfaces in Contact by'surroundin them with an inclosing shell, which is fi led with a material fusible at a predetermined degree of heat.

, When a tensile strain. is applied to the two members of the link, the 'oblique abutting surfaces tend to separate the members and. cause a compression of the fusible material, which is, however, sufficient to resist the tensile strain applied until it has become -softened by heat. The contact of the oblique surfaces of the two members of the link is, therefore, determined by the compressi-A bility of the fusible material lcontained in the inclosing shell or case.

Referring to the accompanying drawings, 1 denotes a plate having on one end an eX- tension 2, provided with an eye 3 to receive a hook or the eye of a cable 4. The plate 1 is provided with a shell 5 inclosing a space 6, preferably rectangular in cross section, and adapted to receive a mass of fusible metal 7. The central portion of the plate 1 is bent inward at a sharp angle providing an oblique surface 8.' In the formation of the link a plate 9 having an angular' 4bend producing an oblique surface 10, fitting the oblique surface 8 `on the plate 1, is inserted within the shall 5 in the position shown in central view in Fig. 2. The remaining space within the shell 5 is then filled with the metal 7, fusible at a predetermined degree of heat. i

' Any tensile strain a plied to the two members 1 and 9 will Ibo resisted by the oblique surfaces 8 and 10 so long at the latter are held in contact by the incompressibility of the fusible material 7. When the fusible material 7,however, has become softened by heat and its compressibility decreased, the oblique surface 8 will act as a cam surface and crowd the plate 9 into the mass of com-l pressible metal 7 luntil the plate 9 slips by the tip 11, causing a separation in the ink I claim,

1. A fusible link adapted to receive a tensile strain, comprising two members'having contacting surfaces oblique to the li'ne of tensile strain, and means for holding said oblique surfaces in contact, comprising a mass of metal fusible at a grec of heat, in contact with the side of one of said members .op )osite to the other inember, and non fusi le inclosing means attached to the other member in contact with the outer side of'said fusible material.

2. As an article of manufacture a fusible ceive a tensile strain, and having contacting surfaces oblique to .the line of tensile strain, a shell or case attached to one of said members and inclosing the other member, with an intervening s ace to allow for the insertion or withdrawa of said inclosed member, and a material filling said intervening space, fusi, ble at a predetermined degree of heat.

3. The within described fusible link, consisting of plates having interlocking oblique surfaces, an inclosing shell, and an inclosed Vmetal fusible at a predetermined degree of I heat, by' Vwhich said interlocked surfaces are 1 held in contact.

predetermined de link comprising two members adapted to re- 4. In a, fusible link, a plate having e V- sheped projection, a second plate having a corresponding \lshaped recess to receive said projection, and means for holding said 5 plates in contact, comprising a metal fusible at a predetermined degree of heat and epplied to one of said plates opposite to its con vtacting surface, sind a shell attached to the other of seid plates and inclosingT said fusible metal.

GEORGE I. RGCKWOOD. Vitnesses PENELOPE COMBERBACH, RUFUS B. FOWLER. 

